Golfer classification method, golfer classification system and golf club selection method

ABSTRACT

A golfer classification method in which, in order to classify a golfer based on his/her swing behavior, a first head speed HS 1  of a short iron when the golfer hits a golf ball with the short iron is measured; a second head speed HS 2  and a blow angle of a long iron when the golfer hits a golf ball with the long iron are measured; the head speed ratio HS 2/ HS 1  is calculated; by comparing the blow angle with a first threshold, the golfer is classified into a down blow group or a non down blow group; and by comparing the head speed ratio HS 2/ HS 1  with a second threshold, the golfer classified into the down blow group is further classified into a first down blow group or a second down blow group. A golf club selection method in which, for the golfer classified by the golfer classification method, a suitable golf club is selected.

BACKGROUND OF THE INVENTION

The present invention relates to a golfer classification method, a golfer classification system and a golf club selection method, in which a golfer is classified based on his/her swing behavior, and a golf club suitable for the classified golfer is selected.

In recent years, a golfer classification method and system for classifying golfers based on their swing behaviors have been proposed in Japanese Patent Application Publication No. 2010-046539 (hereinafter, Patent Document 1). In this method, a golfer is classified based on vertical and horizontal approach angles of a golf club head when the golfer hits a golf ball.

The Patent Document 1 also proposed a golf club selection method for selecting an optimum golf club for the classified golfer. In this method, an optimum loft angle and an optimum face of golf club are selected in advance for each of groups of golfers classified based on their swing behaviors.

SUMMARY OF THE INVENTION

In the golfer classification method, golf club selection method and golfer classification system of the Patent Document 1, the types of the golf clubs are not considered, therefore, it is only possible to select a loft angle and a face of golf club suitable for the golfer. Namely, the above-mentioned method can not select a type of a golf club suitable for the golfer from various types of golf clubs, for example, a long iron as a small number iron club, non-iron-type clubs such as utility club and fairway wood club.

In general, a long iron have higher controllability, and it is possible to hit a golf ball low. But, depending on the golfer, the probability of missed shots is high, and there is a possibility that the desired carry distance can not be achieved. Thus, it is difficult to quantitatively select the type of golf club most suitable for the golfer which allows for the golfer to lessen possible missed shot and achieve the desired carry distance.

It is therefore, an object of the present invention to provide a golfer classification method, a golfer classification system and a golf club selecting method, in which a golfer is classified based on his/her swing behavior, and a type of golf club most suitable for the classified golfer can be selected.

According to one aspect of the present invention, a golfer classification method for classifying a golfer based on his/her swing behavior, comprises:

a first measuring step of measuring a first head speed HS1 of a short iron when the golfer hits a golf ball with the short iron, by the use of a measuring means,

a second measuring step of measuring a second head speed HS2 and a blow angle θ of a long iron when the golfer hits a golf ball with the long iron, by the use of the measuring means,

a calculating step of calculating a head speed ratio HS2/HS1 which is the ratio of the second head speed HS2 to the first head speed HS1 by the use of a calculating means,

a first classifying step of classifying the golfer into a down blow group or a non down blow group, by a determining means, based on the blow angle θ of the long iron and a predetermined first threshold value therefor, and

a second classifying step in which, based on the head speed ratio HS2/HS1 and a predetermined second threshold value therefor, the golfer classified into the down blow group is further classified, by the determining means, into a first down blow group where the head speed ratio HS2/HS1 is more than the second threshold value, or a second down blow group where the head speed ratio HS2/HS1 is not more than the second threshold value.

The golfer classification method according the present invention may includes the following optional features/steps:

(1) the first threshold value is −0.5 degrees;

(2) a step of determining the second threshold value based on a club length ratio L2/L1 which is the ratio of the club length L2 of the long iron to the club length L1 of the short iron;

(3) a step of determining the second threshold value within a range of from 97% to 103% of a club length ratio L2/L1 which is the ratio of the club length L2 of the long iron to the club length L1 of the short iron;

(4) a third measuring step of measuring, by the use of the measuring means, a third head speed HS3 of a non-iron-type club when the golfer hits a golf ball with the non-iron-type club.

According to another aspect of the present invention, a golf club selection method, which is for selecting a type of golf club for the golfer classified by the golfer classification method according to the invention, comprises:

a step of selecting, for the golfer classified into the non down blow group, a non-iron-type club as a golf club corresponding to a low number golf club of an iron set, by a selecting means, and

a step of selecting, for the golfer classified into the first down blow group, a long iron as a golf club Corresponding to a low number golf club of the iron set, by the selecting means.

According to still another aspect of the present invention, a golf club selection method, which is for selecting a type of golf club for the golfer classified by the golfer classification method including the above-mentioned optional step (4), comprises steps implemented by a selecting means which are:

a step of selecting, for the golfer classified into the non down blow group, a non-iron-type club as a golf club corresponding to a low number golf club of an iron set;

a step of selecting, for the golfer classified into the first down blow group, the long iron as a golf club corresponding to a low number golf club of an iron set;

a step of selecting,

for the golfer classified into the second down blow group,

as a golf club Corresponding to a low number golf club of an iron set,

the long iron if the head speed HS3 is not more than a predetermined third threshold value, or

a non-iron-type club if the head speed HS3 is more than the third threshold value.

According to yet still another aspect of the present invention, a golfer classification system for classifying a golfer based on his/her swing behavior, comprises:

a measuring means for measuring a behavior of a golf club head,

a calculating means for calculating measured data obtained by the measuring means,

a determining means for classifying the golfer based on calculated results obtained by the calculating means and the measured data, wherein

the measuring means measures a first head speed HS1 of a short iron when the golfer hits a golf ball with the short iron, and a second head speed HS2 and a blow angle θ of a long iron when the golfer hit a golf ball with the long iron,

the calculating means calculates a head speed ratio HS2/HS1 which is the ratio of the second head speed HS2 to the first head speed HS1,

the determining means classifies the golfer into a down blow group or a non-down blow group based on the measured blow angle θ of the long iron and a predetermined first threshold value therefor, and

the determining means further classifies the golfer belonging to the down blow group into

a first-down blow group where the head speed ratio HS2/HS1 is more than a predetermined second threshold value, or

a second down blow group where the head speed ratio HS2/HS1 is not more than the second threshold value.

In the golfer classification method and system according to the present invention, it is possible to classify a golfer into the down blow group or the non-down blow group based on the blow angle. The golfer in the down blow group is further classified into the first down-blow group where the head speed ratio HS2/HS1 is larger, or the second down-blow group where the head speed ratio HS2/HS1 is smaller.

According to the inventors' experiments, it is necessary for obtaining a desired carry distance with a long iron, to improve the head speed by utilizing the length of the long club and down blow swing.

The golfer classification method and system according to the present invention can readily classify a golfer into a group according to which a type of golf club suitable for the golfer can be selected, therefore, missed shot may be lessened, and desired carry distance may be easily achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a golfer classification system as an embodiment of the present invention.

FIG. 2 is a diagram for explaining a mode of measuring the swing behavior in this embodiment.

FIG. 3(A) and 3(B) show swing paths for explaining down blow and upper blow, respectively.

FIG. 4 is a flow chart of a golfer classification method incorporated in a golf club selecting method as an embodiment of the present invention.

FIG. 5 is a flow chart showing an example of the classification process S5.

FIG. 6 is a diagram showing the classification result of the golfer.

FIG. 7 is a flow chart showing an example of the selection process S6.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of present invention will now be described in detail in conjunction with the accompanying drawings.

As shown in FIG. 1, a golfer classification system 1 as an embodiment of present invention includes a measuring means 2 and an analysis means 3.

As shown in FIG. 2, the measuring means 2 is for measuring the swing behavior when a golfer G swings a golf club C, in particular, the behavior of the head H of the golf club C when hitting a golf ball B.

In this example, the measuring means 2 can measure the head speed HS and blow angle θ of the golf club C.

The head speed HS is the speed of the head H at the time of hitting the golf ball B.

The blow angle θ is the angle, with respect to the horizontal plane HP, of a tangent to the swing path So at the time of hitting the golf ball B.

As shown in FIG. 3(A), the “down blow” is such that the lowest point LP of the swing path is located in the front of the hitting position of the golf ball B in the ball hitting direction.

As shown in FIG. 3(B), “upper blow” is such that the lowest point LP of the swing path is located in the rear of the hitting position of the golf ball B in the ball hitting direction.

The measuring means 2 outputs data D about the measured blow angle θ.

For example, the blow angle θ of the data D is a negative value in the case of the “down blow”, and a positive value in the case of the “upper blow”.

If the blow angle θ is zero or very small values, such swing is called “level blow”.

In this specification, the “level blow” is defined by the blow angle θ of from −0.5 to +0.5 degrees.

The measuring means 2 may be one including an imaging device such as a high-speed camera for example. In this case, it is desirable that a marker is attached to the golf club C to easily recognize the position of the golf club head.

It is however, preferable that the measuring means 2 is one capable of being attached to the golf club C as shown in FIG. 2. In this case, the measurement is possible without limited to a specific measuring location, and hand carry is possible.

As the analysis means 3, a computer, e.g. a laptop or notebook computer, is used. Further, handheld devices, e.g. tablets, multi-function mobile telephones and the like may be used.

The data D from the measuring means 2 is input to the analysis means 3. The inputting of the data D is made via a wired or wireless connection or a storage medium for example.

The analysis means 3 makes an analysis of the data D according to a procedure defined in advance. In this embodiment, as shown in FIG. 1, the analyzing means 3 comprises a processing means 4 in which the data D is input, an input means 5 for inputting information from the outside, and an output means 6 for outputting the analysis result.

The processing means 4 comprises

a calculating means 7 for calculating the data D according to a predetermined procedure,

a judging means 8 for classifying the golfer G according to a predetermined procedure, based on the data D and the calculated results, and

a selecting means 9 for selecting a type of golf club C for the classified golfer G.

The input means 5 may be any input means capable of inputting information, for example, a keyboard, a mouse, a touch panel and the like.

The output means 6 may be any device capable of displaying visual information such as a monitor and printer.

The golfer classification method is for classifying a target golfer G based on his/her swing behavior.

FIG. 4 shows a flow chart of the golfer classification method.

In this embodiment, firstly, a first measuring step S1 is performed, which step is for measuring a behavior of a head H of a prescribed golf club C when the golfer G hits a golf ball B with the golf club C by the use of the measuring means 2.

In the first measuring step S1 in this embodiment, the measured is a first head speed HS1 of the head H of a short iron C1 when the golfer G hit the golf ball B with the short iron C1. For example, the short iron C1 in this embodiment has a loft angle of more than 37 degrees, and a club length L1 of less than 37 inches.

The first measuring step S1 can be that for measuring a single swing, or that for measuring multiple swings to obtain their average value to be output.

Next, a second measuring step S2 is performed, which step is for measuring a behavior of a head H of a prescribed golf club C different from that used in the step S1, when the golfer G hits a golf ball B with this different golf club C, by the use of the measuring means 2.

In the second measuring step S2 in this embodiment, the measured is a second head speed HS2 and a blow angle θ of the head H of a long iron C2 when the golfer G hit the golf ball B with the long iron C2.

For example, the long iron C2 in this embodiment has a loft angle of less than 25 degrees, and a club length L2 of more than 38 inches.

The second measuring step S2 can be that for measuring a single swing, or that for measuring multiple swings to calculate their average value to be output.

Next, a third measuring step S3 is performed, which step is for measuring a behavior of a head H of a different kind of golf club C from those used in the step S1 and S2, when the golfer G hits a golf ball B with this different kind of golf club C, by the use of the measuring means 2.

In the third measuring step S3 in this embodiment, the measured is a third head speed HS3 of the head H of a non-iron-type club C3 when the golfer G hit the golf ball B with this non-iron-type club C3.

For example, the non-iron-type club C3 in this embodiment is a utility club whose club length L3 is close to the club length L2 of the long iron C2.

Aside from such utility club, the non-iron-type club C3 may be a fairway wood for example.

The third measuring step S3 can be that for measuring a single swing, or that for measuring multiple swings to calculate their average value to be output.

The third measuring step S3 may be performed only when the golfer G is classified by the judging means 8 into the after-mentioned second down-blowing group.

The sequence to perform the first measurement step S1, the second measuring step S2 and the third measurement step S3 is not limited to this order. These steps can be performed in any order. For example, it is possible to firstly perform the second measuring step S2.

Next, by the calculating means 7, a calculating step S4 is performed for calculating a head speed ratio HS2/HS1 which is the ratio of the second head speed HS2 to the first head speed HS1.

Next, a classification process S5 for classifying the golfer G is performed by the judging means 8.

FIG. 5 shows a flowchart of the classification process S5. In this embodiment, firstly, a first classifying step S51 is performed to classify the golfer G based on a blow angle θ when the golfer G hits a golf ball B with the long iron C2 and a predetermined first threshold value T1 therefor.

Incidentally, the first threshold value T1 is inputted to the judging means 8 in advance by the input means 5.

In the first classifying step S51, by comparing the blow angle θ with the first threshold value T1, the golfer G is classified into the down blow group where the golfer G tends to make down blow swing, or the non-down blow group where the golfer G tends to make level blow or upper blow swing.

In this embodiment, the first threshold value T1 for the blow angle θ is −0.5 degrees.

In the first classifying step S51, data about which group the golfer G belongs to is added, as golfer's own information, to a golfers' data set for identifying the golfer G.

In the first classifying step S51, if the golfer G has been classified into the non-down blow group, then the classification process S5 ends at the step S51.

In the first classifying step S51, if the golfer G has been classified into the down blow group, then the classification process S5 progresses to a second classifying step S52 of further classifying the golfer G by the judging means 8, based on the head speed ratio HS2/HS1 and a second threshold value T2 therefor.

Preferably, the second threshold value T2 is determined based on the club length ratio L2/L1 which is the ratio of the club length L2 of the long iron C2 to the club length L1 of the short iron C1.

Incidentally, the club lengths L1 and L2 are inputted to the judging means 8 in advance by the input means 5.

Such second threshold value T2 may be an indicator for confirming the improvement in the head speed HS by utilizing the long club length.

In this example, the second threshold value T2 is set in a range of from 97% to 103% of the club length ratio L2/L1.

If the second threshold value T2 is less than 97% of the club length ratio L2/L1, there is a possibility that the improvement in the head speed HS by utilizing the club length can not be expected.

If the second threshold value T2 is more than of 103% of the club length ratio L2/L1, it may not lead to appropriate classification because it will force the golfer G to excessively improve the head speed HS.

More preferably, the second threshold value T2 is set in a range of from 98% to 100% of the club length ratio L2/L1.

Such second threshold value T2 may be an indicator for classifying the golfer G into the first-down blow group where missed shot is less and the probability of achieving the desired distance is high if the long iron C2 is used.

In the second classifying step S52 in this embodiment, the golfer G in the down blow group is classified into

a first down blow group where the head speed ratio HS2/HS1 is more than the second threshold value T2, or

a second down blow group where the head speed ratio H52/HS1 is not more than the second threshold value T2.

In such second classifying step S52, data about which group the golfer G belongs to is added, as golfer's own information, to the above-mentioned golfers' data set for identifying the golfer G.

In the second classifying step S52, if the golfer G has been classified into the first down blow group, then the classification process S5 ends at the step S52.

In the second classifying step S52, if the golfer G is classified into the second down blow group, then the classification process S5 progresses to a third classifying step S53 of further classifying the golfer G by the judging means 8, based on the third head speed HS3 of the non-iron-type club C3 and a third threshold value T3 therefor.

The third threshold value T3 is determined based on the second head speed HS2 of the long iron C2.

Preferably, the third threshold value T3 is equal to the second head speed HS2.

Such third threshold T3 may be an indicator for judging the golfer G whether the probability of achieving the desired distance by using the non-iron-type club C3 is high or not.

In the third classifying step S53, the golfer G in the second blow-down group is further classified into

a second non-iron group where the third head speed HS3 is more than the third threshold value T3, or

a second iron group where the third head speed HS3 is not more than the third threshold value T3,

In the third classifying step S53, data about which group the golfer G belongs to is added, as golfer's own information, to the above-mentioned golfers' data set for identifying the golfer G.

In the golfer classification method, preferably and in this embodiment, the result about the classification of the golfer G made through the classification process S5 is output through the output means 6.

FIG. 6 shows an example of such output which is a distribution map whose horizontal axis and vertical axis represent the head speed ratio HS2/HS1 and the blow angle θ, respectively. In this example, the results of classification about plural golfers G are plotted.

Incidentally, the output means 6 may be configured such that, when outputting the results of classification, for example, for the golfers G classified into the second down-blowing group, the colors of the plots are changed between the second non-iron group and the second iron group.

FIG. 4 shows a flowchart of the golf club selection method for selecting a type of golf club C most suitable for the golfer G already classified by the golfer classification method as described above.

The golf club selection method in this embodiment includes a selection process S6 as shown in FIG. 7 which shows a flowchart of the selection process S6.

In the selection process S6, firstly, there is performed a step S61 of judging if the golfer G is classified into the down blow group.

If it is judged in the step S61 such that the golfer G is not in the down blow group, in other words, the golfer G is in the non down blow group, then there is performed a step S62 of selecting a non-iron type club C3 which is most suitable for the golfer as a golf club C corresponding to a low number golf club of an iron set.

Usually, golfers G in the non-down blow group are liable to make missed shot if the long iron C2 is used, therefore, it is recommended to use a non-iron-type club C3 instead of the long iron C2.

If it is judged in the step S61 such that the golfer G is classified into the down blow group, then there is performed a step S63 of judging if the golfer G is classified into the first down-blowing group.

If it is judged in the step S63 such that the golfer G is classified into the first down-blowing group, then there is performed a step S64 of selecting the long iron C2 which is most suitable for the golfer as a golf club C corresponding to a low number golf club of an iron set.

In the case of golfers G in the first down blow group, improvement in the head speed HS can be expected by utilizing the down blow swing and the length of the long club, therefore, the long iron C2 having higher controllability is selected without change.

If it is judged in the step S63 such that the golfer G is not classified into the first down-blowing group, in other words, the golfer G is classified into the second down-blow group, then there is performed a step S65 of judging if the golfer G is classified into the second non-iron group.

If it is judged in the step S65 such that the golfer G is classified into the second non-iron group, then there is performed a step S62 of selecting the non-iron-type club C3 which is most suitable for the golfer as a golf club C corresponding to a low number golf club of an iron set.

In the case of golfers G in the second non-iron group, improvement in the head speed HS can be expected by using the non-iron-type club C3 owing to its longer club length as compared to the long iron C2, therefore, the non-iron-type club C3 is selected to use it instead of the long iron C2.

If it is judged in the step S65 such that the golfer G is not classified into the second non-iron group, namely, the golfer G is classified into the second iron group, then there is performed a step S64 of selecting the long iron C2 which is most suitable for the golfer as a golf club C corresponding to a low number golf club of an iron set.

In the case of golfers G in the second iron group, improvement in the head speed HS by utilizing the length of the long club Can not be expected with respect to both of the long iron C2 and the non-iron-type club C3, but the long Iron C2 is selected because the long Iron C2 having higher controllability is more suitable for the golfer making down blow swing.

Finally, the type of the golf club C selected by the selection process S6 is output through the output means 6. After performing such outputting step, the golf club selection method ends.

While detailed description has been made of preferable embodiments of the present invention, the present invention can be embodied in various forms without being limited to the illustrated embodiments.

Working Examples

According to the golfer classification method in this embodiment, eight golfers G1-G8 were classified, wherein the swing behavior of each of the golfers when swinging golf clubs described in the following common specifications, was measured. The measurement was made ten times per one golf club, and the average value was obtained.

<Common Specifications>

Short iron: #9 iron, club length 36 inches, loft angle 39 degrees

Long iron: #5 iron, club length 38 inches, loft angle 24 degrees Non-iron-type club: #6 utility, club length 39 inches, loft angle 25 degrees

First threshold value: −0.5 degrees

Second threshold value: 98.5% of the club length ratio (38/36×0.985=approx. 1.04)

Third threshold value: values of head speed of #5 iron of respective golfers

The measured results are shown in Table 1, and the classification results are plotted in the distribution map shown in FIG. 6.

TABLE 1 golfer G1 G2 G3 G4 G5 G6 G7 G8 #9 iron's head 32.4 32.3 32.6 33.1 32 32.2 32.1 31.8 speed (m/s) #5 iron's head 35.2 34 33.6 33.9 34.7 34.5 32.7 32.9 speed (m/s) #5 iron's blow −3.4 −0.8 −1.3 −2.3 0.3 −0.1 1.5 0.2 angle (deg.) #6 utility's 36.5 35.2 35.2 35 35.1 34.9 34.8 34.7 head speed (m/s) head speed 1.09 1.05 1.03 1.02 1.08 1.07 1.02 1.03 ratio (#5 iron/ #9 iron)

In the case of the classification results show in FIG. 6, both of the golfers G3 and G4 classified into the second down-blowing group, showed the #6 utility's head speed more than the third threshold value, and further classified into the second non-iron group, and

as a golf club Corresponding to a low number golf club of an iron set, the non-iron-type club was selected for the golfers classified into the non-down blow group and the second down blow group, and the long iron was selected for the golfers classified into the first-down blow group. 

1. A golfer classification method for classifying a golfer based on his/her swing behavior, comprising: a first measuring step of measuring a first head speed HS1 of a short iron when the golfer hits a golf ball with the short iron, by the use of a measuring means, a second measuring step of measuring a second head speed HS2 and a blow angle θ of a long iron when the golfer hits a golf ball with the long iron. by the use of the measuring means, a calculating step of calculating a head speed ratio HS2/HS1 which is the ratio of the second head speed HS2 to the first head speed HS1 by the use of a calculating means, a first classifying step of classifying the golfer into a down blow group or a non down blow group, by a determining means, based on the blow angle θ of the long iron and a predetermined first threshold value therefor, and a second classifying step in which, based on the head speed ratio HS2/HS1 and a predetermined second threshold value therefor, the golfer classified into the down blow group is further classified, by the determining means, into a first down blow group where the head speed ratio HS2/HS1 is more than the second threshold value, or a second down blow group where the head speed ratio HS2/HS1 is not more than the second threshold value.
 2. The golfer classification method according to claim 1, wherein the first threshold value is −0.5 degrees.
 3. The golfer classification method according to claim 1, which further comprises a step of determining the second threshold value based on a club length ratio L2/L1 which is the ratio of the club length L2 of the long iron to the club length L1 of the short iron.
 4. The golfer classification method according to claim 2, which further comprises a step of determining the second threshold value based on a club length ratio L2/L1 which is the ratio of the club length L2 of the long iron to the club length L1 of the short iron.
 5. The golfer classification method according to claim 1, which further comprises a step of determining the second threshold value within a range of from 97% to 103% of a club length ratio L2/L1 which is the ratio of the club length L2 of the long iron to the club length L1 of the short iron.
 6. The golfer classification method according to claim 2, which further comprises a step of determining the second threshold value within a range of from 97% to 103% of a club length ratio L2/L1 which is the ratio of the club length L2 of the long iron to the club length L1 of the short iron.
 7. The golfer classification method according to claim 1, which further comprises a third measuring step of measuring, by the use of the measuring means, a third head speed HS3 of a non-iron-type club when the golfer hits a golf ball with the non-iron-type club.
 8. The golfer classification method according to claim 2, which further comprises a third measuring step of measuring, by the use of the measuring means, a third head speed HS3 of a non-iron-type club when the golfer hits a golf ball with the non-iron-type club.
 9. The golfer classification method according to claim 3, which further comprises a third measuring step of measuring, by the use of the measuring means, a third head speed HS3 of a non-iron-type club when the golfer hits a golf ball with the non-iron-type club.
 10. The golfer classification method according to claim 4, which further comprises a third measuring step of measuring, by the use of the measuring means, a third head speed HS3 of a non-iron-type club when the golfer hits a golf ball with the non-iron-type club.
 11. A golf club selection method for selecting a type of golf club for the golfer classified by the golfer classification method according to claim 1, comprising: a step of selecting, for the golfer classified into the non down blow group, a non-iron-type club as a golf club corresponding to a low number golf club of an iron set, by a selecting means, and a step of selecting, for the golfer classified into the first down blow group, a long iron as a golf club Corresponding to a low number golf club of the iron set, by the selecting means.
 12. A golf club selection method for selecting a type of golf club for the golfer classified by the golfer classification method according to claim 7, comprising steps implemented by a selecting means which are: a step of selecting, for the golfer classified into the non down blow group, a non-iron-type club as a golf club corresponding to a low number golf club of an iron set; a step of selecting, for the golfer classified into the first down blow group, the long iron as a golf club corresponding to a low number golf club of an iron set; a step of selecting, for the golfer classified into the second down blow group, as a golf club Corresponding to a low number golf club of an iron set, the long iron if the head speed HS3 is not more than a predetermined third threshold value, or a non-iron-type club if the head speed HS3 is more than the third threshold value.
 13. A golfer classification system for classifying a golfer based on his/her swing behavior, comprising: a measuring means for measuring a behavior of a golf club head, a calculating means for calculating measured data obtained by the measuring means, a determining means for classifying the golfer based on calculated results obtained by the calculating means and the measured data, wherein the measuring means measures a first head speed HS1 of a short iron when the golfer hits a golf ball with the short iron, and a second head speed HS2 and a blow angle θ of a long iron when the golfer hit a golf ball with the long iron, the calculating means calculates a head speed ratio HS2/HS1 which is the ratio of the second head speed HS2 to the first head speed HS1, the determining means classifies the golfer into a down blow groups or non-down blow group based on the measured blow angle θ of the long iron and a predetermined first threshold value therefor, and the determining means further classifies the golfer belonging to the down blow group into a first-down blow group where the head speed ratio HS2/HS1 is more than a predetermined second threshold value, or a second down blow group where the head speed ratio HS2/HS1 is not more than the second threshold value. 